// Copyright 2012 the V8 project authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef V8_REGEXP_REGEXP_MACRO_ASSEMBLER_IRREGEXP_H_
#define V8_REGEXP_REGEXP_MACRO_ASSEMBLER_IRREGEXP_H_

#include "src/regexp/regexp-macro-assembler.h"

namespace v8 {
namespace internal {

    // A light-weight assembler for the Irregexp byte code.
    class V8_EXPORT_PRIVATE RegExpMacroAssemblerIrregexp
        : public RegExpMacroAssembler {
    public:
        // Create an assembler. Instructions and relocation information are emitted
        // into a buffer, with the instructions starting from the beginning and the
        // relocation information starting from the end of the buffer. See CodeDesc
        // for a detailed comment on the layout (globals.h).
        //
        // The assembler allocates and grows its own buffer, and buffer_size
        // determines the initial buffer size. The buffer is owned by the assembler
        // and deallocated upon destruction of the assembler.
        RegExpMacroAssemblerIrregexp(Isolate* isolate, Zone* zone);
        virtual ~RegExpMacroAssemblerIrregexp();
        // The byte-code interpreter checks on each push anyway.
        virtual int stack_limit_slack() { return 1; }
        virtual bool CanReadUnaligned() { return false; }
        virtual void Bind(Label* label);
        virtual void AdvanceCurrentPosition(int by); // Signed cp change.
        virtual void PopCurrentPosition();
        virtual void PushCurrentPosition();
        virtual void Backtrack();
        virtual void GoTo(Label* label);
        virtual void PushBacktrack(Label* label);
        virtual bool Succeed();
        virtual void Fail();
        virtual void PopRegister(int register_index);
        virtual void PushRegister(int register_index,
            StackCheckFlag check_stack_limit);
        virtual void AdvanceRegister(int reg, int by); // r[reg] += by.
        virtual void SetCurrentPositionFromEnd(int by);
        virtual void SetRegister(int register_index, int to);
        virtual void WriteCurrentPositionToRegister(int reg, int cp_offset);
        virtual void ClearRegisters(int reg_from, int reg_to);
        virtual void ReadCurrentPositionFromRegister(int reg);
        virtual void WriteStackPointerToRegister(int reg);
        virtual void ReadStackPointerFromRegister(int reg);
        virtual void LoadCurrentCharacter(int cp_offset,
            Label* on_end_of_input,
            bool check_bounds = true,
            int characters = 1);
        virtual void CheckCharacter(unsigned c, Label* on_equal);
        virtual void CheckCharacterAfterAnd(unsigned c,
            unsigned mask,
            Label* on_equal);
        virtual void CheckCharacterGT(uc16 limit, Label* on_greater);
        virtual void CheckCharacterLT(uc16 limit, Label* on_less);
        virtual void CheckGreedyLoop(Label* on_tos_equals_current_position);
        virtual void CheckAtStart(Label* on_at_start);
        virtual void CheckNotAtStart(int cp_offset, Label* on_not_at_start);
        virtual void CheckNotCharacter(unsigned c, Label* on_not_equal);
        virtual void CheckNotCharacterAfterAnd(unsigned c,
            unsigned mask,
            Label* on_not_equal);
        virtual void CheckNotCharacterAfterMinusAnd(uc16 c,
            uc16 minus,
            uc16 mask,
            Label* on_not_equal);
        virtual void CheckCharacterInRange(uc16 from,
            uc16 to,
            Label* on_in_range);
        virtual void CheckCharacterNotInRange(uc16 from,
            uc16 to,
            Label* on_not_in_range);
        virtual void CheckBitInTable(Handle<ByteArray> table, Label* on_bit_set);
        virtual void CheckNotBackReference(int start_reg, bool read_backward,
            Label* on_no_match);
        virtual void CheckNotBackReferenceIgnoreCase(int start_reg,
            bool read_backward, bool unicode,
            Label* on_no_match);
        virtual void IfRegisterLT(int register_index, int comparand, Label* if_lt);
        virtual void IfRegisterGE(int register_index, int comparand, Label* if_ge);
        virtual void IfRegisterEqPos(int register_index, Label* if_eq);

        virtual IrregexpImplementation Implementation();
        virtual Handle<HeapObject> GetCode(Handle<String> source);

    private:
        void Expand();
        // Code and bitmap emission.
        inline void EmitOrLink(Label* label);
        inline void Emit32(uint32_t x);
        inline void Emit16(uint32_t x);
        inline void Emit8(uint32_t x);
        inline void Emit(uint32_t bc, uint32_t arg);
        // Bytecode buffer.
        int length();
        void Copy(byte* a);

        // The buffer into which code and relocation info are generated.
        Vector<byte> buffer_;
        // The program counter.
        int pc_;
        // True if the assembler owns the buffer, false if buffer is external.
        bool own_buffer_;
        Label backtrack_;

        int advance_current_start_;
        int advance_current_offset_;
        int advance_current_end_;

        Isolate* isolate_;

        static const int kInvalidPC = -1;

        DISALLOW_IMPLICIT_CONSTRUCTORS(RegExpMacroAssemblerIrregexp);
    };

} // namespace internal
} // namespace v8

#endif // V8_REGEXP_REGEXP_MACRO_ASSEMBLER_IRREGEXP_H_
